W. Royal Stokes, a onetime professor of classics who became a major presence in jazz as a Washington-based radio disc jockey, journalist and author known for his oral histories of musicians’ lives, died May 1 at his home in Elkins, W.Va. He was 90.

The cause was myelodysplastic syndrome, a condition related to leukemia, said his son Sutton Stokes.

Mr. Stokes was, by his own admission, an accidental jazz critic with no formal musical training. His instrument was the typewriter.

But he was drawn to the music from his teen years in D.C., when he saw trumpeter Louis Armstrong perform at the old Club Bali on 14th Street NW. After a peripatetic career that included Army service, college in Seattle and a decade as a classics professor, Mr. Stokes returned to D.C. in the early 1970s.

He began to write for small journals and, in 1972, launched the radio show “I Thought I Heard Buddy Bolden Say . . .” on WGTB, the Georgetown University station. The program’s title was taken from the lyrics of Jelly Roll Morton’s “Buddy Bolden’s Blues,” about an early New Orleans cornet player.

Mr. Stokes contributed reviews to The Washington Post from 1979 to 1986, often chronicling several performances a week.

As much as he was steeped in jazz tradition, he also wrote with authority about the contemporary scene. In an appreciation of the multi-instrumentalist Rahsaan Roland Kirk, who was part of the modern jazz movement of the 1960s, he wrote:

“Blind from birth, Kirk could hear melodies in the roar of airplane engines and recognize the rhythms of friends’ footsteps in a crowded club.

“A saxophonist who blended the traditional and the avant-garde, he could play three horns at once and was famous for his self-duets on flute and nose flute. His stamina was legendary; he once blew nonstop for more than two hours at a London club and was annoyed when his feat did not make it into the Guinness Book of Records.”

Mr. Stokes often conducted lengthy interviews with musicians, which he reworked into books beginning with 1991’s “The Jazz Scene: An Informal History From New Orleans to 1990.”

“Jazz is the only original American art form,” he wrote, “and it’s strange that everybody in the world knows that except the citizens of the United States of America.”

His other titles included “Growing Up With Jazz” (2005), in which musicians — many of them women — described their early influences. Throughout his career, Mr. Stokes championed female singers and instrumentalists, who often battled entrenched sexism while struggling to find an audience.

Mr. Stokes was the editor of JazzTimes magazine from 1988 to 1990 and then edited Jazz Notes, published by the Jazz Journalists Association, from 1992 to 2001. He also had a second radio program on Washington’s WPFW-FM and received the 2014 Lifetime Achievement Award from the Jazz Journalists Association.

“What he’s done is so exceptional,” jazz writer Gary Giddins said while presenting the award. “He’s let the musicians speak for themselves. His books are absolutely indispensable because he stays out of the way and allows them the freedom to talk about their music and themselves.”

William Royal Stokes was born June 27, 1930, in Washington. His father, an amateur poet and playwright, had a management job with a Baltimore steel company. His mother was a homemaker.

Mr. Stokes spent part of his childhood in Baltimore and on Gibson Island in the Chesapeake Bay before returning to Washington. He was first drawn to jazz from his brother’s record collection and by his visits to D.C. jazz clubs. (One of his early homes, near Dupont Circle, later became an after-hours jazz and gambling joint.)

After graduating in 1948 from the District’s Woodrow Wilson High School, he served in the Army, attended the University of Maryland and married for the first time. He moved to Seattle in the 1950s and received a bachelor’s degree in history in 1958 and a master’s degree in classics in 1960, both from the University of Washington. He earned a doctorate in classics from Yale University in 1965.

He taught classics and ancient history at colleges including the University of Washington, the University of Pittsburgh and Tufts University in Massachusetts. As the 1960s wore on, Mr. Stokes became increasingly drawn to the antiwar movement and the student subculture and grew his hair to his shoulders.

He left academic life in 1969 after teaching at the University of Colorado, seeking “something more connected with the current world,” he told The Post in February. He drifted to Austin, New Hampshire and Maine before resettling in Washington in 1971. Broke at the time, he worked at a food co-op in Mount Rainier, Md., and as a dishwasher at a Georgetown vegetarian restaurant.

He lived in Silver Spring, Md., for many years before moving to West Virginia in 2006. He presented his extensive collection of jazz books and recordings to the University of the District of Columbia in 2010.

His marriages to Mary Dolores Perkins and Lynn Carroll ended in divorce. In 1971, he married Erika Hartmann. In addition to his wife, of Elkins, survivors include their two sons, Sutton Stokes of Elkins and Neale Stokes of Los Angeles; and two grandchildren.

Mr. Stokes said his devotion to jazz was derived in part from the way the music erases social and racial barriers and in part because it seems connected to his previous studies of the classics.

“In my reading and my research of the classics,” he told The Post, “I always had the sense that the tradition was so important. No Greek or Latin poet could escape the influence of Homer, for instance. I look at jazz in the same way: a continuum.”